diff options
Diffstat (limited to 'data/m4/vasnprintf2.diff')
| -rw-r--r-- | data/m4/vasnprintf2.diff | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/data/m4/vasnprintf2.diff b/data/m4/vasnprintf2.diff new file mode 100644 index 000000000..54ab5e88a --- /dev/null +++ b/data/m4/vasnprintf2.diff @@ -0,0 +1,35 @@ +diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c +index fecaf27..2e4eb19 100644 +--- a/lib/vasnprintf.c ++++ b/lib/vasnprintf.c +@@ -4869,10 +4869,9 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, + #endif + *fbp = dp->conversion; + #if USE_SNPRINTF +-# if ! (((__GLIBC__ > 2 \ +- || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) \ +- && !defined __UCLIBC__) \ +- || (defined __APPLE__ && defined __MACH__) \ ++# if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) \ ++ && !defined __UCLIBC__) \ ++ || (defined __APPLE__ && defined __MACH__) \ + || ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)) + fbp[1] = '%'; + fbp[2] = 'n'; +@@ -4887,9 +4886,13 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, + in format strings in writable memory may crash the program + (if compiled with _FORTIFY_SOURCE=2), so we should avoid it + in this situation. */ +- /* macOS 10.13 High Sierra behaves like glibc with +- _FORTIFY_SOURCE=2, and older macOS releases +- presumably do not need %n. */ ++ /* On Mac OS X 10.3 or newer, we know that snprintf's return ++ value conforms to ISO C 99: the tests gl_SNPRINTF_RETVAL_C99 ++ and gl_SNPRINTF_TRUNCATION_C99 pass. ++ Therefore we can avoid using %n in this situation. ++ On Mac OS X 10.13 or newer, the use of %n in format strings ++ in writable memory by default crashes the program, so we ++ should avoid it in this situation. */ + /* On native Windows systems (such as mingw), we can avoid using + %n because: + - Although the gl_SNPRINTF_TRUNCATION_C99 test fails, |